1. Field of the Invention
The present invention generally relates to a hoist structure and more particularly a hoist constructed of three basic components releasably connected to each other to facilitate assembly and disassembly and to facilitate portability of the hoist to a job site in a disassembled and collapsed or knocked-down position and then being readily set up or assembled at the job site with the main frame or base component including structural features to facilitate support thereof on a supporting surface, deck, platform or the like, connection to a truck bed and support by wheeled units.
2. Description of the Prior Art
Many devices have been provided for use in lifting loads such as overhead cranes employed in many industrial plants and mobile cranes used in many construction operations and other uses with such devices usually including an elongated boom supported in an upwardly inclined position and provided with a flexible cable entrained over a pulley at the outer end of the boom and provided with a load-engaging structure at the free end thereof and connected with a winch drum at the end of the boom connected to the vehicle on which the boom is mounted. Such mobile cranes are quite expensive and due to their weight and cumbersome nature, they are usually moved to a job site by the use of a trailer type vehicle. Other hoisting devices of lightweight construction are also known with some of these devices being foldable or collapsible, vehicle mounted and the like. Representative of the prior patents illustrating developments in this field of endeavor are U.S. Pat. Nos. 1,798,456, 2,340,351, 2,491,357, 2,509,435 and 3,450,386.